Oil topping up with different types

[verona]

I have searched this site high and low and can't find the answer to my question. The bike in question is a 26,000 miler GS1150R 2000. At
my last service the BMW dealer filled up the bike with 15w50 mineral
oil. My question is would it be okay to top up the oil using 20w50
mineral oil as I still have some left over from previously.

I am sure there is a tosser out there somewhere that can answer my
simpleton question.

Cheers. Jay

 

[Mouse]

I would say yes, but I can't justify it scientifically

 

[Steve]

I would say yes, but I can't justify it scientifically

Neither can I, but I do it all the time. Car, bike, lawn mower - share and share alike...

 

[harry]

oil spec mix

Have done it for years and mixed my oils as well.
read years ago it did no harm

 

[cookie]

wouldn't worry me.

 

[Greg Masters]

...filled up the bike with 15w50 mineral
oil. My question is would it be okay to top up the oil using 20w50
mineral oil ...?

Mix it 50:50 and you'd end up with 17½w50 grade!

Joking apart, that's what you would get! For those of us that still run bikes requiring fork oil, you can adjust the damping by mixing different weight oils.

Providing that you're mixing the same basic type of oil (engine oil, bike engine oil, gearbox oil), you can mix pretty much anything (different viscosities, mineral or synth, different brands etc) except you MUST NOT mix mineral oil (or synthetic) and castor oils (like Castrol R30).

Greg

 

[verona]

Thanks for the replies gents, just as I thought. Its always better to
be safe than sorry.

Cheers. Jay